Adjustable head for t-squares



(NoModeL) E. LIDBANE. ADJUST-ABLE HEAD FOR T-SQUA-RES.

Patented Sept. 28, 1 886.

was STATES PATENT ()Frrce.

.EZRA L. DEANE, OFHOLYOKE, MASSACHUSETTS.

ADJUSTABLE HEAD FOR T-SQUARSES.

SFECIEICAI'IQN forming part of Letters Patent No. 349,697, datedSeptember'28, 1886.

Application filed February 20, 1886. Serial No. 192,625. (No model.)

To all whom it may concern.-

Be it known that I, EZRA L. DEANE, a citizen of the United States,residing at Holyoke, in the county of Hampden and State ofMassachusetts, have invented new and useful Improvements in T-Squares,of which the following is a specification.

This invention relates to improvements in T-squares, the object being toprovide a square of this class with an improved adjustable head-bar; andthe invention consists in the peculiar arrangement of parts, ashereinafter fully described, and set forth in the claims.

In the drawing, forming part of this specification, ',is illustrated inplan view a T-square the lower end of the blade being shown broken off)constructed according to my invention.

In the drawing, A is the blade, and B is the head, of the square, madeof either wood or metal, said head and blade being rigidly securedtogether, as shown.

D is a head-bar pivotally attached by one end to one end of the head Bby a link, a, the ends of the latter being attached to the said head andbar by screws, as shown. Said link and the below-described head and barconnecnections are of sufficient length to sustain the bar D, somewhatremoved from the edge of the head B, so that the bar may have a freeswinging movement toward and from the adjoining edge of said head. Theend of the bar D opposite that which is connected to the head B by saidlink has a metallic arm, e, secured thereto, which projects beyond theend of the bar, and has the screw-threaded rod 0 pivotally secured to itand extending opposite the end of the head B, as shown, and said rod isprovided with an adjustingnut, v, and with a setnut, 20. The end of thehead B is provided with a bifurcated arm, e, secured thereon oppositesaid arm e, and, like the latter, projecting beyond the end of saidhead, and the biflneated portion of arm 6 spreads sufficiently to admitsaid adjusting-nut o therebetween,

and the said rod 0 passes transversely through said bifurcated parts ofarm 6 and nut o, and the said set-nut w is screwed on the end of saidrod 0, as shown.

It is well known that wooden Tsquares are seldom acorn-ate and requirefrequent adj ustment, and the above-described improvements provideconvenient and efficient means for adjusting a square to correct itsangles. By turning nut w toward the end of rod 0 the latter is made freeto be moved, together with the end of bar D, to which it is connected,by turning the said nut 1*, thereby swinging said bar until its edge isbrought exactly at right angles to the edge of the blade A, or swingingsaid bar to a position relative to the head, other than at a right anglethereto, and when the bar is brought to the desired position the set-nutis screwed against arm 6, locking the rod 0 to said arm. The nut wmay beomitted, if desired, but without it the bar D may become inadvertentlymoved out of adjustment by the too easy rotation of the nut o. A

What I claim as my invention.is-

1. The combination, with the head B of a T-square, and with the head-barD, pivotally connected by one end to said head, of an arm, e, on saidbar opposite its pivoted end, having a screw-rod attached thereto, anarm, 0, on said head opposite the arm on said bar, having a bifurcatedend through which said screw-rod passes, and an adjusting-nut operating011 said rod between the bifurcated parts of said arm e, substantiallyas set forth.

2'. In combination with the head B of a T- square, the head-bar D,pivoted by one end to one end of said head B, the screw-rod 0, and theadjusting-nut 1;, having an engagement with the ends of arms,substantially as described, on the ends of said head and bar,substantially as set forth.

3. In combination, the head B of a T square having the bifurcated arm 6'thereon, the swinging head-bar D, having the arm 6.

thereon, the screw-rod 0, connected to the latter and passing througharm 0, and the nuts 1 and w, substantially as set forth.

EZRA L. DEANE-

